While the larger and faster container ships and their shore-side cranes have been getting much of the press of late, there remains a huge volume of bulk cargo shipping. A long established manner of handling bulk cargos has been to move them by crane from a deep-sea ship to inland or coastal barges.
This can be done directly, with the ship at anchor away from the docks as is done in many ports around the world, or the transfer can take place from ships at anchor in the lower reaches of a river. In either case the transfer for bulk cargos such as grains or mineral ores can be carried out with out the need of expensive piers and shore-side structures. With increasing awareness of the damage that can occur from harbor dredging, the utilization of deeper waters away from shore can result in significant fiscal and environmental savings.
Speed with safety is an essential consideration in trans-loading cargo whether loading from barges to ship or ship to barge. Cargotec’s McGregor Crane Division has extensive experience in developing floating cranes to meet these criteria. Unlike a shore mounted cargo crane, the heavy duty, high performance, floating crane provides the flexibility to berth anywhere around a barge for optimal efficiency and operability. The floating crane also presents unique engineering challenges when it comes to accommodating the stability requirements of the barge on which the crane is mounted as well as providing the required power for the crane to do its job.
One way to maintain platform stability is to utilize electric engines to drive the crane’s hydraulic systems. In this way diesel-driven electric generators can be mounted on the barge deck while transmitting power to the electric motor mounted in the elevated crane. McGregor supplies its floating cranes with two times 100% power requirements. This redundancy allows the crane to continue working even if one engine has to be taken off line for maintenance.
In a recent collaboration with Cummins Marine, this flexibility has been further enhanced with the development of a fully containerized 1000 kVA/1290 kW generator set. Each set will be powered by aV-16-cylinder Cummins K50-DM diesel that is certified as IMO Tier II emission reduction compliant. In addition to the fully outfitted engines and generators, each 40-foot long high–cube ISO standard container contains an electronic menu-driven user interface, and tankage for 5000 litres of fuel fitted with high and low level sensors.
The container also contains starting batteries and is fitted with end as well as side service doors. It also involves a break resistor with automatic engagement on the reverse power detection to avoid engine over-speed. Cooling is achieved by shell and tube heat exchangers and external seawater pump. There are also emergency stop buttons on the exterior of the container as well as on the control panel adjacent to the personnel doors. The sound-insulated container is also fitted with flush mounted external drain points for lube-oil, fuel and water.
This will mean that, in addition to duel engine redundancy on McGregor floating crane barges, it will be possible to remove and containerized engine and transport it to a shore-based shop for servicing, without the crane suffering any downtime.
Illustration courtesy of Novetec
For further information:
Communication & Media Coordinator – Europe
Cummins Distribution Europe
Cummins Holland B.V.
3316 KH Dordrecht
Tel +31 78 6530 927
Mobile: +31 (0)6 110 11 075